Mix together low-fat quark, yoghurt and powdered sugar. Soak the gelatine in cold water, squeeze it out and heat it in a saucepan until it has dissolved. Stir a tablespoon of the cream into the gelatin. Now add the mixture to the cream and stir well.
Rub the zest of the orange and lemon and squeeze out the juice. Scrape out the vanilla pod. Add everything to the cream and stir. Whip the whipped cream until stiff and fold into the orange-lemon cream. Chill in the refrigerator for a few hours.